Minimize image sensor i/o and conductor counts in endoscope applications

ABSTRACT

The disclosure extends to systems and methods for reducing the area of an image sensor by employing bi-directional pads used for both image data issuance and configuration command reception and internal supply voltage generation, for reducing the number of conductors in an endoscope system.

CROSS-REFERENCE TO RELATED APPLICATIONS

This application is a continuation of U.S. application Ser. No.17/111,286, filed Dec. 3, 2020, which is a continuation of U.S.application Ser. No. 16/418,871, filed May 21, 2019 (now U.S. Pat. No.10,881,272), and which is a continuation of U.S. application Ser. No.14/214,794, filed Mar. 15, 2014 (now U.S. Pat. No. 10,750,933), andwhich claims the benefit of U.S. Provisional Application No. 61/791,547,filed Mar. 15, 2013, and U.S. Provisional Application No. 61/790,590,filed Mar. 15, 2013, all of which are incorporated herein by referencein their entireties, including but not limited to those portions thatspecifically appear hereinafter, the incorporation by reference beingmade with the following exception: In the event that any portion of anyof the above-referenced applications is inconsistent with thisapplication, this application supersedes said above-referencedapplications.

STATEMENT REGARDING FEDERALLY SPONSORED RESEARCH OR DEVELOPMENT

Not Applicable.

BACKGROUND

Advances in technology have provided advances in imaging capabilitiesfor medical use. One area that has enjoyed some of the most beneficialadvances is that of endoscopic surgical procedures because of theadvances in the components that make up an endoscope.

The disclosure relates generally to minimizing the area and reducing thenumber of inputs and outputs of an image sensor for use in an endoscopicdevice. The features and advantages of the disclosure will be set forthin the description which follows, and in part will be apparent from thedescription, or may be learned by the practice of the disclosure withoutundue experimentation. The features and advantages of the disclosure maybe realized and obtained by means of the instruments and combinationsparticularly pointed out in the appended claims.

BRIEF DESCRIPTION OF THE DRAWINGS

Non-limiting and non-exhaustive implementations of the disclosure aredescribed with reference to the following figures, wherein likereference numerals refer to like parts throughout the various viewsunless otherwise specified. Advantages of the disclosure will becomebetter understood with regard to the following description andaccompanying drawings.

FIG. 1 illustrates an implementation of an endoscopic system inaccordance with the principles and teachings of the disclosure;

FIG. 2 illustrates an implementation of an internal up-conversion from asupplied low voltage to the higher voltage in accordance with theprinciples and teachings of the disclosure;

FIG. 3A illustrates an implementation of a down regulator that is basedupon a switch-cap DC-DC down-convertor in accordance with the principlesand teachings of the disclosure;

FIG. 3B illustrates an implementation of a down regulator that is basedupon a Low Drop Out regulator in accordance with the principles andteachings of the disclosure;

FIG. 4 illustrates an implementation of a frame timing structure inaccordance with the principles and teachings of the disclosure;

FIG. 5 illustrates an implementation of connections between endoscopebuttons and a sensor based upon a resistance network in accordance withthe principles and teachings of the disclosure;

FIG. 6 illustrates an implementation in which an angular position Hallsensor delivers an analog voltage directly to a CMOS image sensor inaccordance with the principles and teachings of the disclosure;

FIG. 7 illustrates implementations of encoding examples for digital datawords within frame data in accordance with the principles and teachingsof the disclosure;

FIG. 8 illustrates an embodiment of hardware in accordance with theprinciples and teachings of the disclosure;

FIGS. 9A and 9B illustrate views of an implementation of an imagingsensor having a plurality of pixel arrays for producing a threedimensional image in accordance with the teachings and principles of thedisclosure;

FIGS. 10A and 10B illustrate views of an implementation of an imagingsensor built on a plurality of substrates, wherein a plurality of pixelcolumns forming the pixel array are located on the first substrate and aplurality of circuit columns are located on a second substrate andshowing an electrical connection and communication between one column ofpixels to its associated or corresponding column of circuitry; and

FIGS. 11A and 11B illustrate views of an implementation of an imagingsensor having a plurality of pixel arrays for producing a threedimensional image, wherein the plurality of pixel arrays and the imagesensor are built on a plurality of substrates.

DETAILED DESCRIPTION

The disclosure extends to methods, systems, and computer based productsfor digital imaging that may be primarily suited to medicalapplications. In the following description of the disclosure, referenceis made to the accompanying drawings, which form a part hereof, and inwhich is shown by way of illustration specific implementations in whichthe disclosure may be practiced. It is understood that otherimplementations may be utilized and structural changes may be madewithout departing from the scope of the disclosure.

In describing and claiming the subject matter of the disclosure, thefollowing terminology will be used in accordance with the definitionsset out below.

It must be noted that, as used in this specification and the appendedclaims, the singular forms “a,” “an,” and “the” include plural referentsunless the context clearly dictates otherwise.

As used herein, the terms “comprising,” “including,” “containing,”“characterized by,” and grammatical equivalents thereof are inclusive oropen-ended terms that do not exclude additional, unrecited elements ormethod steps.

As used herein, the phrase “consisting of”′ and grammatical equivalentsthereof exclude any element or step not specified in the claim.

As used herein, the phrase “consisting essentially of” and grammaticalequivalents thereof limit the scope of a claim to the specifiedmaterials or steps and those that do not materially affect the basic andnovel characteristic or characteristics of the claimed disclosure.

As used herein, the term “proximal” shall refer broadly to the conceptof a portion nearest an origin.

As used herein, the term “distal” shall generally refer to the oppositeof proximal, and thus to the concept of a portion farther from anorigin, or a furthest portion, depending upon the context.

Referring now to FIG. 1, there is illustrated a digital imaging systemthat utilizes minimal pad interconnects in order to reduce the size ofthe image sensor for use with an endoscopic device within a lightdeficient environment. The digital imaging system 101 illustrated inFIG. 1 may comprise an endoscopic device 102 for use in ambient lightdeficient environment. The endoscopic device 102, in turn, may includean endoscope 104, an endoscope housing 106 (e.g., hand piece and/orcamera head), control unit 108, an electronic communication 120, such asan electronic cable, light source 109, a light cable 126, such as afiber optic cable, connected to light source 109 and endoscopic device102, display 112, and imaging device 114 (e.g., image sensor and relatedcircuitry etc.). Note that in this example, to facilitate discussion,the endoscope device 104, endoscope housing 106, control unit 108, lightsource 109, display 112, and imaging device 114 are each shownindividually with respect to one another. However, it is to beappreciated and understood that this is not to be interpreted aslimiting, and any one or more of these components can be integratedand/or connected in any suitable way.

It will be appreciated that imaging device 114 may include an imagesensor comprising a pixel array, wherein a scene is continuously focusedonto the pixel array. It will be appreciated that the image sensorsenses reflected electromagnetic radiation using or with the pixelarray. The pixel array generates image data and an image frame iscreated from the image data. A processor 124 may detect image texturesand edges within the image frame and may further enhance textures andedges within the image frame. The processor 124, whether in the housing106 or at the control unit 108, may also retrieve from memory propertiespertaining to the pixel technology and the applied sensor gain to assessan expectation for the magnitude of noise within an image frame createdby said sensor and using said noise expectation to control the edgeenhancement application. A stream of images may be created bysequentially combining a plurality of the image frames.

It will be appreciated that traditional rod-lens endoscopes, used forlaparoscopy, arthroscopy, urology, gynecology and ENT (ear-nose-throat)procedures, are expensive to manufacture owing to their complex opticalcomposition. The incident image information is transported in theoptical domain all the way along its length. Typically it is opticallycoupled to a hand-piece unit, wherein the image sensing device(s)reside. This type of rigid endoscope is also delicate and prone todamage during handling, use and sterilization. The necessary repair andsterilization processes add further expense to each procedure for whichthey are utilized.

Advances in imaging technology have led to complementary metal-oxidesemiconductor (CMOS) sensors that are cheap to manufacture and arehighly customizable. Much of the external circuitry that was necessaryto operate charge-coupled device (CCD) based sensors may be integratedinto the same chip as the pixel array and lower operation voltages areneeded. Therefore CMOS-based cameras are much cheaper and easier tomanufacture and may be much more versatile than their CCD-basedcounterparts. For similar reasons, CMOS sensors are appearing more andmore within endoscope systems.

Much cheaper endoscopes may be realized by placing the image sensingdevice at the distal end, since the optical transport assembly may beeffectively replaced by a simple plastic lens stack, not dissimilar towhat exists in a typical cell phone camera. They may be so inexpensivein fact that it may make more financial sense to have them bemanufactured for single use only, to be subsequently disposed of orrecycled, since that negates the repair and sterilization processes.

The difficulty in creating such an endoscope solution is in maintainingimage quality since the region into which the sensor must fit is highlyspace constrained in both dimensions. Reducing the sensor area generallyimplies a reduction in pixel count and/or pixel area which may impactthe resolution, sensitivity and dynamic range. Normally, endoscopesystems are geared toward sensing steady broadband illumination andproviding color information by segmenting the array into pixels of threeor more ranges of wavelength sensitivity. This is done by crafting anindividual color filter over each pixel, the Bayer mosaic being the mostcommon solution. One way to avoid resolution loss is to eliminate thecolor filters since with the Bayer mosaic e.g. there may be up to afactor 1/√2 loss in luminance resolution (in x or y) as compared withthe native array resolution. The color information in such a case can beprovided by pulsing a laser or LED-based illuminants with differentwavelengths or combinations thereof during separate frame captures.Applicant has developed such systems and devices, which allow for highdefinition quality at progressive frame rates of 60 Hz or higher byvirtue of a special sensor design. Additional developments by Applicantallow for the peripheral circuitry to be reduced to its minimal areawhile transmitting image data off chip in the digital domain.

It will be appreciated by those of skill in the art that each bond padoccupies significant physical space on a chip. Each bond pad is used toprovide power or input/output signals to and from the sensor chip.Therefore in striving for minimal area it is desirable to reduce thenumber of bond pads as much as possible. This disclosure described astrategy for reducing pad count by combining digital input and outputfunctionality into the same bi-directional pads. During imagetransmission they act as differential outputs. Then during a definedportion of each frame, they switch direction, in order to enablecommands to be received. This requires that the camera controlelectronics have the commands issued to the sensor synchronized to thetiming of the frame. This approach may be useful in the context of manyCMOS sensor applications since sensor cost scales with chip area.

Another way to reduce the pad count described herein, is to use only asingle external power supply and use, e.g., internal DC to DC convertersor regulators to provide for multiple internal (e.g., analog anddigital) supplies.

Further to this, in the context of an endoscope system, the simplicityand manufacturability can be enhanced by customizing the image sensor inorder to receive commands and information from the endoscope hand-piece.The information may then be subsequently incorporated into the outputdata issued by the sensor. This reduces the overall conductor count fromendoscope to camera system. Such information sources may include userinstigated button events or measurements of the angle of rotation of theendoscope with respect to the hand-piece. Angular measurements arenecessitated by certain embodiments of endoscopes having their imagesensors placed at the distal end.

CMOS image sensors typically incorporate two different power supplies,necessitating three pads: VDD1, VDD2 & GND. The higher of the twovoltages is used predominantly for the purpose of biasing the pixelarray. Occasionally it will also be used to power input/output circuits.The lower voltage would typically be used to power the peripheral analogcircuitry and the digital portion of the sensor, where applicable.Sometimes however, certain analog readout elements are powered using thehigher supply voltage, which is usually in the range of about 3V toabout 4V.

One strategy for reducing the pad count is to supply only a single powerlevel and have the second one derived on-chip. This would also beeffective in removing a power circuit (regulator etc.) from the camerasystem.

FIG. 2 illustrates one implementation of an internal up-conversion froma supplied low voltage to the higher voltage. This example is based upona switch-cap DC-DC up-convertor 200. Both the flying cap (C1) and thedecoupling cap (C2) are internal. The low power voltage (low VDD)supplies the up-convertor along with the relevant internal circuitry. Itwill be appreciated that an oscillator (not illustrated in FIG. 2)delivers the correct switching pattern to Si through S4. This oscillatormay be powered from the low voltage and proper level shifting needs tohappen to have the correct switching voltage levels. The generated powersupply may be tuned by carefully choosing the oscillator frequency, theinternal resistance of the switch and the ratio between the flying capand the decoupling cap (C1/C2).

In another implementation, the supplied voltage may be the high voltagesupply (high VDD). FIGS. 3A and 3B depict two examples of a downregulator that may be used in this configuration. FIG. 3A illustrates asystem that is based upon a switch-cap DC-DC down-convertor 300. Itshould be noted that in an implementation, similar considerations may beapplied as for the convertor in FIG. 2.

FIG. 3B illustrates an implementation comprising a Low Drop Outregulator (LDO) 302 is based upon a linear circuit. The internalreference may come from a simple resistive divider or from a band gapreference generator. Although less susceptible to pick-up noise (asthere are no switching elements), the LDO is often less efficient thanits switch-cap counterpart.

It should be noted that in general, up-conversion may be used morereadily than down regulators. This is because the sensor high voltage isusually less critical in terms of noise and requires less currentconsumption. Therefore the specifications for an up-converter are lessdemanding.

The CMOS image sensors of the disclosure may have a plurality ofinternal on-chip registers. These provide the sensor with flexibilityand optimization options. The presence of these registers usuallynecessitates dedicated digital pads, in order that they may beconfigured using a defined slow-control protocol.

A system and method for eliminating or reducing these digital pads,while maintaining configurable registers may comprise the following. Thesystem and method may be based on an approach that uses dual purposepads for both input and output. These pads are designed to automaticallyswitch between the output and input states at well-defined times. Whenthe pads are acting as outputs, image data and other types of data areissued from the sensor. When the pads are in the input state they mayreceive slow control commands. To facilitate this, the frame period maybe divided into three defined states, rolling-readout (image data isissued), service-lines (other types of data issued) and theconfiguration phase, during which the pads become inputs. The camerasystem needs to know what state the sensor pads are in at all times.During the rolling-readout and service-line phases, the camera systemmay not issue slow-control commands.

FIG. 4 Illustrates an implementation of a method of timing. The frametiming structure 400 is depicted in FIG. 4 wherein the configuration andservice-line phases are also used to pulse the light in pulsedillumination-based systems.

For reasons of cost, simplicity and manufacturability, it may beadvantageous to conceive of an endoscope with a minimal number ofconductors, with no active components other than the sensor, and a cablethat solely incorporates the communication protocol between the sensorand the remainder of the camera system. When combined withbi-directional sensor data pads 405 and internal voltage generation (asper the methods described herein), the cable may be as minimal as havingjust as many data wires as needed to support the requisite imagebandwidth and one power supply requiring just two wires (i.e., power andground).

In a conventional modern endoscope, dedicated electrical connections maybe needed for operations that are not directly related to the sensor.For example there are extra wires to service hand-piece buttons. Thesemay be wires connected directly to the button, or alternatively to alocal microcontroller that also serves also other functions.

In other examples, sensors may be needed to determine the angularposition of the endoscope. The angle information should be relayed usingvarious methods and structures to the image processing chain (ISP)within the camera system.

One strategy for reducing the endoscope conductor count is that any lowspeed analog and digital signals, instead of being sent directly to thecamera system, may be re-routed to the CMOS image sensor. Within thesensor the signals may be digitally converted, if necessary, beforebeing encoded alongside the image data or in lieu of pixel data withinspecial service lines. Such as a strategy may eliminate the need forextra wires in the endoscope cable and extra active components withinthe endoscope hand-piece or lumen. Issuing the data at the sensor framerate may also allow for increased (i.e., faster) system response. Thecamera system simply needs to decode this “hidden” information and actaccordingly.

FIG. 5 illustrates an implementation of connections between theendoscope buttons 505 and the sensor 555 based upon a resistancenetwork. In this approach, a series of on-chip comparators 510 mayconvert the analog signal into a digital word ready to be issued asoutput data.

FIG. 6 illustrates an implementation in which an angular position HallEffect sensor 622 delivers an analog voltage directly to the CMOS imagesensor 655. In this case, the analog voltage may be converted by anon-chip analog-digital converter (ADC) and inserted within the frame.

FIG. 7 illustrates two possible encoding examples for digital data wordswithin the frame data. They may be, for example, inserted in the rowheader 705 or by replacing “pixel” data within the service rows 710. Itshould be noted that there are multiple other configurations forencoding digital data words within the CMOS sensor image data and allsuch configurations are intended to fall within the scope of thisdisclosure.

It should also be noted that FIG. 5 and FIG. 6 are merely exemplary andother forms of data may be sent to the CMOS sensor other than thatdescribed above without departing from the scope of the disclosure. Suchdata comprises digital data for which case a serial communicationprotocol would serve the purpose well.

Implementations of the disclosure may comprise or utilize a specialpurpose or general-purpose computer including computer hardware, suchas, for example, one or more processors and system memory, as discussedin greater detail below.

Implementations within the scope of the disclosure may also includephysical and other computer-readable media for carrying or storingcomputer-executable instructions and/or data structures. Suchcomputer-readable media can be any available media that can be accessedby a general purpose or special purpose computer system.Computer-readable media that store computer-executable instructions arecomputer storage media (devices). Computer-readable media that carrycomputer-executable instructions are transmission media. Thus, by way ofexample, and not limitation, implementations of the disclosure cancomprise at least two distinctly different kinds of computer-readablemedia: computer storage media (devices) and transmission media.

Computer storage media (devices) includes RAM, ROM, EEPROM, CD-ROM,solid state drives (“SSDs”) (e.g., based on RAM), Flash memory,phase-change memory (“PCM”), other types of memory, other optical diskstorage, magnetic disk storage or other magnetic storage devices, or anyother medium which can be used to store desired program code means inthe form of computer-executable instructions or data structures andwhich can be accessed by a general purpose or special purpose computer.

A “network” is defined as one or more data links that enable thetransport of electronic data between computer systems and/or modulesand/or other electronic devices. In an implementation, a sensor andcamera control unit may be networked in order to communicate with eachother, and other components, connected over the network to which theyare connected. When information is transferred or provided over anetwork or another communications connection (either hardwired,wireless, or a combination of hardwired or wireless) to a computer, thecomputer properly views the connection as a transmission medium.Transmissions media can include a network and/or data links which can beused to carry desired program code means in the form ofcomputer-executable instructions or data structures and which can beaccessed by a general purpose or special purpose computer. Combinationsof the above should also be included within the scope ofcomputer-readable media.

As can be seen in FIG. 8, various computer system components, programcode means in the form of computer-executable instructions or datastructures that can be transferred automatically from transmission mediato computer storage media (devices) (or vice versa). For example,computer-executable instructions or data structures received over anetwork or data link can be buffered in RAM within a network interfacemodule (e.g., a “NIC”), and then eventually transferred to computersystem RAM and/or to less volatile computer storage media (devices) at acomputer system. RAM can also include solid state drives (SSDs or PCIxbased real time memory tiered Storage, such as FusionIO). Thus, itshould be understood that computer storage media (devices) can beincluded in computer system components that also (or even primarily)utilize transmission media.

Computer-executable instructions comprise, for example, instructions anddata which, when executed at a processor, cause a general purposecomputer, special purpose computer, or special purpose processing deviceto perform a certain function or group of functions. The computerexecutable instructions may be, for example, binaries, intermediateformat instructions such as assembly language, or even source code.Although the subject matter has been described in language specific tostructural features and/or methodological acts, it is to be understoodthat the subject matter defined in the appended claims is notnecessarily limited to the described features or acts described above.Rather, the described features and acts are disclosed as example formsof implementing the claims.

Those skilled in the art will appreciate that the disclosure may bepracticed in network computing environments with many types of computersystem configurations, including, personal computers, desktop computers,laptop computers, message processors, control units, camera controlunits, hand-held devices, hand pieces, multi-processor systems,microprocessor-based or programmable consumer electronics, network PCs,minicomputers, mainframe computers, mobile telephones, PDAs, tablets,pagers, routers, switches, various storage devices, and the like. Itshould be noted that any of the above mentioned computing devices may beprovided by or located within a brick and mortar location. Thedisclosure may also be practiced in distributed system environmentswhere local and remote computer systems, which are linked (either byhardwired data links, wireless data links, or by a combination ofhardwired and wireless data links) through a network, both performtasks. In a distributed system environment, program modules may belocated in both local and remote memory storage devices.

Further, where appropriate, functions described herein can be performedin one or more of: hardware, software, firmware, digital components, oranalog components. For example, one or more application specificintegrated circuits (ASICs) or field programmable gate arrays can beprogrammed to carry out one or more of the systems and proceduresdescribed herein. Certain terms are used throughout the followingdescription and Claims to refer to particular system components. As oneskilled in the art will appreciate, components may be referred to bydifferent names. This document does not intend to distinguish betweencomponents that differ in name, but not function.

FIG. 8 is a block diagram illustrating an example computing device 800.Computing device 800 may be used to perform various procedures, such asthose discussed herein. Computing device 800 can function as a server, aclient, or any other computing entity. Computing device can performvarious monitoring functions as discussed herein, and can execute one ormore application programs, such as the application programs describedherein. Computing device 800 can be any of a wide variety of computingdevices, such as a desktop computer, a notebook computer, a servercomputer, a handheld computer, camera control unit, tablet computer andthe like.

Computing device 800 includes one or more processor(s) 802, one or morememory device(s) 804, one or more interface(s) 806, one or more massstorage device(s) 808, one or more Input/Output (I/O) device(s) 810, anda display device 830 all of which are coupled to a bus 812. Processor(s)802 include one or more processors or controllers that executeinstructions stored in memory device(s) 804 and/or mass storagedevice(s) 808. Processor(s) 802 may also include various types ofcomputer-readable media, such as cache memory.

Memory device(s) 804 include various computer-readable media, such asvolatile memory (e.g., random access memory (RAM) 814) and/ornonvolatile memory (e.g., read-only memory (ROM) 816). Memory device(s)804 may also include rewritable ROM, such as Flash memory.

Mass storage device(s) 808 include various computer readable media, suchas magnetic tapes, magnetic disks, optical disks, solid-state memory(e.g., Flash memory), and so forth. As shown in FIG. 8, a particularmass storage device is a hard disk drive 824. Various drives may also beincluded in mass storage device(s) 808 to enable reading from and/orwriting to the various computer readable media. Mass storage device(s)808 include removable media 826 and/or non-removable media.

I/O device(s) 810 include various devices that allow data and/or otherinformation to be input to or retrieved from computing device 800.Example I/O device(s) 810 include digital imaging devices,electromagnetic sensors and emitters, cursor control devices, keyboards,keypads, microphones, monitors or other display devices, speakers,printers, network interface cards, modems, lenses, CCDs or other imagecapture devices, and the like.

Display device 830 includes any type of device capable of displayinginformation to one or more users of computing device 800. Examples ofdisplay device 830 include a monitor, display terminal, video projectiondevice, and the like.

Interface(s) 806 include various interfaces that allow computing device800 to interact with other systems, devices, or computing environments.Example interface(s) 806 may include any number of different networkinterfaces 820, such as interfaces to local area networks (LANs), widearea networks (WANs), wireless networks, and the Internet. Otherinterface(s) include user interface 818 and peripheral device interface822. The interface(s) 806 may also include one or more user interfaceelements 818. The interface(s) 806 may also include one or moreperipheral interfaces such as interfaces for printers, pointing devices(mice, track pad, etc.), keyboards, and the like.

Bus 812 allows processor(s) 802, memory device(s) 804, interface(s) 806,mass storage device(s) 808, and I/O device(s) 810 to communicate withone another, as well as other devices or components coupled to bus 812.Bus 812 represents one or more of several types of bus structures, suchas a system bus, PCI bus, IEEE 1394 bus, USB bus, and so forth.

For purposes of illustration, programs and other executable programcomponents are shown herein as discrete blocks, although it isunderstood that such programs and components may reside at various timesin different storage components of computing device 800, and areexecuted by processor(s) 802. Alternatively, the systems and proceduresdescribed herein can be implemented in hardware, or a combination ofhardware, software, and/or firmware. For example, one or moreapplication specific integrated circuits (ASICs) can be programmed tocarry out one or more of the systems and procedures described herein.

It will be appreciated that the disclosure may be used with any imagesensor, whether a CMOS image sensor or CCD image sensor, withoutdeparting from the scope of the disclosure. Further, the image sensormay be located in any location within the overall system, including, butnot limited to, the tip of the endoscope, the hand piece of the imagingdevice or camera, the control unit, or any other location within thesystem without departing from the scope of the disclosure.

Implementations of an image sensor that may be utilized by thedisclosure include, but are not limited to, the following, which aremerely examples of various types of sensors that may be utilized by thedisclosure.

FIGS. 9A and 9B illustrate an implementation of a monolithic sensor 905having a plurality of pixel arrays 910 for producing a three dimensionalimage in accordance with the teachings and principles of the disclosure.Such an implementation may be desirable for three dimensional imagecapture, wherein the two pixel arrays 910 may be offset during use. Inanother implementation, a first pixel array 910 and a second pixel array910 may be dedicated to receiving a predetermined range of wave lengthsof electromagnetic radiation, wherein the first pixel array 910 isdedicated to a different range of wave length electromagnetic radiationthan the second pixel array 910.

FIGS. 10A and 10B illustrate a perspective view of an implementation ofan imaging sensor built on a plurality of substrates 1010, 1011. Asillustrated, a plurality of pixel columns forming the pixel array 1015are located on the first substrate 1011 and a plurality of circuitcolumns 1020 are located on a second substrate 1010. Also illustrated inthe figure are the electrical connection and communication between onecolumn of pixels to its associated or corresponding column of circuitry.

In one implementation, an image sensor, which might otherwise bemanufactured with its pixel array and supporting circuitry on a single,monolithic substrate/chip, may have the pixel array separated from allor a majority of the supporting circuitry. The disclosure may use atleast two substrates/chips, which will be stacked together usingthree-dimensional stacking technology. The first of the twosubstrates/chips may be processed using an image CMOS process. The firstsubstrate/chip may be comprised either of a pixel array exclusively or apixel array surrounded by limited circuitry. The second or subsequentsubstrate/chip may be processed using any process, and does not have tobe from an image CMOS process. The second substrate/chip may be, but isnot limited to, a highly dense digital process in order to integrate avariety and number of functions in a very limited space or area on thesubstrate/chip, or a mixed-mode or analog process in order to integratefor example precise analog functions, or a RF process in order toimplement wireless capability, or MEMS (Micro-Electro-MechanicalSystems) in order to integrate MEMS devices. The image CMOSsubstrate/chip may be stacked with the second or subsequentsubstrate/chip using any three-dimensional technique. The secondsubstrate/chip may support most, or a majority, of the circuitry thatwould have otherwise been implemented in the first image CMOS chip (ifimplemented on a monolithic substrate/chip) as peripheral circuits andtherefore have increased the overall system area while keeping the pixelarray size constant and optimized to the fullest extent possible. Theelectrical connection between the two substrates/chips may be donethrough interconnects, which may be wirebonds, bump and/or TSV (ThroughSilicon Via).

FIGS. 11A and 11B illustrate a perspective view of an implementation ofan imaging sensor having a plurality of pixel arrays for producing athree dimensional image. The three dimensional image sensor may be builton a plurality of substrates 1111 a, 1111 b, 1111 c, and may comprisethe plurality of pixel arrays 1115 a, 1115 b and other associatedcircuitry 1130 a, 1130 b, wherein a plurality of pixel columns formingthe first pixel array and a plurality of pixel columns forming a secondpixel array are located on respective substrates and a plurality ofcircuit columns are located on a separate substrate. Also illustratedare the electrical connections and communications between columns ofpixels to associated or corresponding column of circuitry.

It will be appreciated that the teachings and principles of thedisclosure may be used in a reusable device platform, a limited usedevice platform, a re-posable use device platform, or asingle-use/disposable device platform without departing from the scopeof the disclosure. It will be appreciated that in a re-usable deviceplatform an end-user is responsible for cleaning and sterilization ofthe device. In a limited use device platform the device can be used forsome specified amount of times before becoming inoperable. Typical newdevice is delivered sterile with additional uses requiring the end-userto clean and sterilize before additional uses. In a re-posable usedevice platform a third-party may reprocess the device (e.g., cleans,packages and sterilizes) a single-use device for additional uses at alower cost than a new unit. In a single-use/disposable device platform adevice is provided sterile to the operating room and used only oncebefore being disposed of.

Additionally, the teachings and principles of the disclosure may includeany and all wavelengths of electromagnetic energy, including the visibleand non-visible spectrums, such as infrared (IR), ultraviolet (UV), andX-ray.

It will be appreciated that various features disclosed herein providesignificant advantages and advancements in the art. The followingembodiments are exemplary of some of those features.

In the foregoing Detailed Description of the Disclosure, variousfeatures of the disclosure are grouped together in a single embodimentfor the purpose of streamlining the disclosure. This method ofdisclosure is not to be interpreted as reflecting an intention that theclaimed disclosure requires more features than are expressly recited ineach claim. Rather, inventive aspects lie in less than all features of asingle foregoing disclosed embodiment.

It is to be understood that the above-described arrangements are onlyillustrative of the application of the principles of the disclosure.Numerous modifications and alternative arrangements may be devised bythose skilled in the art without departing from the spirit and scope ofthe disclosure and the appended claims are intended to cover suchmodifications and arrangements.

Thus, while the disclosure has been shown in the drawings and describedabove with particularity and detail, it will be apparent to those ofordinary skill in the art that numerous modifications, including, butnot limited to, variations in size, materials, shape, form, function andmanner of operation, assembly and use may be made without departing fromthe principles and concepts set forth herein.

Further, where appropriate, functions described herein can be performedin one or more of: hardware, software, firmware, digital components, oranalog components. For example, one or more application specificintegrated circuits (ASICs) can be programmed to carry out one or moreof the systems and procedures described herein. Certain terms are usedthroughout the following description and Claims to refer to particularsystem components. As one skilled in the art will appreciate, componentsmay be referred to by different names. This document does not intend todistinguish between components that differ in name, but not function.

1-36. (canceled)
 37. A system comprising: an emitter for emittingelectromagnetic radiation; an image sensor comprising a pixel array forsensing reflected electromagnetic radiation; a plurality ofbidirectional pads in communication with the image sensor, wherein eachof the plurality of bidirectional pads comprises an output state forissuing data and an input state for receiving data; and a control unitin electronic communication with the emitter, the image sensor, and theplurality of bidirectional pads; wherein the control unit synchronizesoperations of the emitter, the image sensor, and the plurality ofbidirectional pads.
 38. The system of claim 37, wherein the control unitsynchronizes operations of the emitter, the image sensor, and theplurality of bidirectional pads based on a pulsing scheme for theemitter, wherein the emitter pulses the electromagnetic radiation whenthe plurality of bidirectional pads are in the input state.
 39. Thesystem of claim 37, wherein the control unit synchronizes operations ofthe emitter, the image sensor, and the plurality of bidirectional padsbased on a readout period for the image sensor, wherein the image sensorreads out pixel data when the plurality of bidirectional pads are in theoutput state.
 40. The system of claim 37, wherein electroniccommunication between the image sensor and the plurality ofbidirectional pads is performed during a plurality of phases, whereinthe plurality of phases comprises: a first service line phase duringwhich the plurality of bidirectional pads are in an output state andnon-image data is output from the image sensor; a rolling readout phasefollowing the first service line phase and during which the plurality ofbidirectional pads are in an output state and image data is output fromthe image sensor; a second service line phase, following the rollingreadout phase, and during which the plurality of bidirectional pads arein an output state and non-image data is output from the image sensor;and a configuration phase during which the plurality of bidirectionalpads are in an input state and instruction data is received by the imagesensor through the plurality of bidirectional pads.
 41. The system ofclaim 40, wherein the control unit synchronizes the operations of theemitter, the image sensor, and the plurality of bidirectional pads suchthat the emitter pulses the electromagnetic radiation during theconfiguration phase.
 42. The system of claim 40, wherein the controlunit synchronizes the operations of the emitter, the image sensor, andthe plurality of bidirectional pads such that the emitter does not emitthe electromagnetic radiation during the rolling readout phase.
 43. Thesystem of claim 37, wherein the image sensor is disposed at a distal endof an endoscope, and wherein a quantity of the plurality ofbidirectional pads is minimized such that the image sensor issufficiently small to be located at the distal end of the endoscope. 44.The system of claim 37, wherein the system is an endoscopicvisualization system, and wherein the emitter emits the electromagneticradiation into a light deficient environment.
 45. The system of claim37, wherein the plurality of bidirectional pads are located on-chip withthe image sensor.
 46. The system of claim 37, wherein the plurality ofbidirectional pads automatically switch between the output state and theinput state, and wherein the plurality of bidirectional pads receiveslow control commands for the image sensor when configured in the inputstate.
 47. The system of claim 37, wherein the plurality ofbidirectional pads are a component of the image sensor, and wherein thesystem further comprises a power wire and a ground wire providingelectronic communication between the control unit and the image sensor,and wherein the control unit electronically communicates with the imagesensor only via the power wire and the ground wire.
 48. The system ofclaim 37, wherein the image sensor is a CMOS image sensor.
 49. Thesystem of claim 37, wherein the image sensor controls the plurality ofbidirectional pads to be configured in the output state or the inputstate, and wherein the control unit synchronizes operations of the imagesensor and the emitter.
 50. The system of claim 49, wherein the controlunit synchronizes operations of the image sensor and the emitter suchthat: the plurality of bidirectional pads receive data in aconfiguration phase when the emitter is emitting a pulse ofelectromagnetic radiation; the plurality of bidirectional pads outputdata in a rolling readout phase when the emitter is not emitting anyelectromagnetic radiation; the emitter pulses a plurality of differentwavelengths of electromagnetic radiation; and the image sensor senses aplurality of different image frames in response to the emitter pulsingthe plurality of different wavelengths of electromagnetic radiation. 51.The system of claim 37, wherein the plurality of bidirectional pads arein: the output state when pixel data is output from the image sensor,wherein the pixel data is generated by exposing the pixel array; and theinput state when receiving control commands for the operation of theimage sensor.
 52. The system of claim 37, further comprising a stateidentifier for identifying when the plurality of bidirectional pads arein the output state or the input state.
 53. The system of claim 37,wherein: the emitter independently pulses a plurality of wavelengths ofelectromagnetic radiation; the pixel array of the image sensor sensespixel data to generate a plurality of image frames; the control unitcauses the emitter to pulse a wavelength of electromagnetic radiationduring a configuration phase for the plurality of bidirectional pads;and the control unit causes the image sensor to read out the pixel arrayduring a rolling readout phase for the plurality of bidirectional pads.54. The system of claim 37, wherein the image sensor is a CMOS imagesensor, and wherein the image sensor is supplied with only a singlepower level.
 55. The system of claim 37, further comprising: anendoscope, wherein the image sensor is disposed at a distal end of theendoscope; a hand piece; a fiber optic cable for communicating theelectromagnetic radiation from the emitter to the distal end of the endoscope; and a state identifier for identifying which state the pluralityof bidirectional pads are in during an operation cycle of the system.56. The system of claim 37, wherein the image sensor comprises a firstpixel array and a second pixel array, wherein the first pixel array andthe second pixel array and configured to sense different ranges ofwavelengths of electromagnetic radiation, and wherein a combination ofthe first pixel array and the second pixel array outputs data forgenerating a three-dimensional image.